[Carotid cavernous fistula: the importance of its opportune diagnosis and treatment to prevent blindness].

A carotid cavernous fistula is an abnormal communication between a branch of the carotid artery and the cavernous sinus generating an arteriovenous fistula that can cause severe ocular damage. We hereby report two cases of carotid cavernous fistulas. A 69-year-old male with a 2-month history of right eyelid swelling and red eye aggrarated by diplopia, exophthalmus, and limitation of ocular movements one week before consulting.